This invention relates to porous molded bodies having a density less than 1 g/cm.sup.3 and having pores of a predetermined size which are distributed isotropically and of which at least 90% are open. The porous bodies are formed from sintered, vitreous and/or crystalline substances.
There are abundant teachings in the prior art relating to porous and foamed molded bodies made from vitreous and/or crystalline substances. Many of these products are used for thermal insulation and as such, they have closed pores to prevent heat transfer.
Another group of products, for instance filter plates, do have open pores of a specific pore size distribution. Conversely, such products are relatively dense and do not have pores of precisely predetermined sizes.
Leached glasses with open pores or channels are also known; however, these too are of higher density.
Still further, a number of products are produced so as to yield pores having special requirements.
References detailing this prior art include the following:
J. G. Wilsmann & G. Solow "Poroses Glas," Silikattechhik 11, (1960) No. 7, pp. 348-352.